adverb
absolutely; utterly; simply; just
Emphatic adverbial form of ただ, used to stress that something is nothing but or entirely the case. Often conveys a strong emotional tone such as regret, gratitude, or helplessness.
ただただ驚くばかりだ。
I am simply astonished.
ただただ感謝の気持ちでいっぱいです。
I am filled with nothing but gratitude.
ただただ時間が過ぎるのを待っていた。
I was just waiting for time to pass.
Rare kanji form using 唯; not commonly used.
ただ is the non-emphatic form meaning 'only' or 'just'; ただただ adds stronger emphasis and emotional weight.
Reduplication of ただ (only, just) for emphasis. The exact historical derivation is straightforward; the kana spelling is standard.